Re: coma, coma, coma
Bob Bond (rgb@postman.ncube.com)
Mon, 1 May 1995 11:20:08 -0700
Coma is inherent in parabolic mirrors as you move off-axis. The
on-axis (center of the viewfinder) area should show no coma, with the
coma increasing radially away from the center. Ruttan's book does a
good job of explaining all of this. The Tele Vue ParaCorr and other
similar coma correctors can clean it up to a remarkable extent. You
may want to track one of these down at a star party to see if helps.
Bob Bond